diff --git a/sys/i386/i386/machdep.c b/sys/i386/i386/machdep.c
index 15dc66459a67..16f23038d8fd 100644
--- a/sys/i386/i386/machdep.c
+++ b/sys/i386/i386/machdep.c
@@ -189,7 +189,13 @@ static void freebsd4_sendsig(sig_t catcher, ksiginfo_t *, sigset_t *mask);
 long Maxmem = 0;
 long realmem = 0;
 
-#define PHYSMAP_SIZE	(2 * 16)
+/*
+ * The number of PHYSMAP entries must be one less than the number of
+ * PHYSSEG entries because the PHYSMAP entry that spans the largest
+ * physical address that is accessible by ISA DMA is split into two
+ * PHYSSEG entries.
+ */
+#define	PHYSMAP_SIZE	(2 * (VM_PHYSSEG_MAX - 1))
 
 vm_paddr_t phys_avail[PHYSMAP_SIZE + 2];
 vm_paddr_t dump_avail[PHYSMAP_SIZE + 2];
diff --git a/sys/i386/include/vmparam.h b/sys/i386/include/vmparam.h
index 7d12c9753b26..8f97e1b53796 100644
--- a/sys/i386/include/vmparam.h
+++ b/sys/i386/include/vmparam.h
@@ -84,6 +84,43 @@
  */
 #define	VM_PHYSSEG_DENSE
 
+/*
+ * The number of PHYSSEG entries must be one greater than the number
+ * of phys_avail entries because the phys_avail entry that spans the
+ * largest physical address that is accessible by ISA DMA is split
+ * into two PHYSSEG entries. 
+ */
+#define	VM_PHYSSEG_MAX		17
+
+/*
+ * Create one free page pool.  Since the i386 kernel virtual address
+ * space does not include a mapping onto the machine's entire physical
+ * memory, VM_FREEPOOL_DIRECT is defined as an alias for the default
+ * pool, VM_FREEPOOL_DEFAULT.
+ */
+#define	VM_NFREEPOOL		1
+#define	VM_FREEPOOL_DEFAULT	0
+#define	VM_FREEPOOL_DIRECT	0
+
+/*
+ * Create two free page lists: VM_FREELIST_DEFAULT is for physical
+ * pages that are above the largest physical address that is
+ * accessible by ISA DMA and VM_FREELIST_ISADMA is for physical pages
+ * that are below that address.
+ */
+#define	VM_NFREELIST		2
+#define	VM_FREELIST_DEFAULT	0
+#define	VM_FREELIST_ISADMA	1
+
+/*
+ * The largest allocation size is 2MB under PAE and 4MB otherwise.
+ */
+#ifdef PAE
+#define	VM_NFREEORDER		10
+#else
+#define	VM_NFREEORDER		11
+#endif
+
 /*
  * Kernel physical load address.
  */